This invention relates in general to a method of making a corrugated container having single layer portions and multiple layer portions.
Single ply corrugated paper for containers is formed of two smooth backing layers, with a corrugated layer glued between. In making the material for corrugated containers, a web of paper from a roll is drawn through a set of corrugating rollers. Then, a backing web is drawn from another roll and glued to the corrugated web. The opposite backing layer is drawn from another roll and glued to the other side of the corrugated web. The result is a composite web of uniform thickness, having three layers, the backing layers and the corrugated layer. Fold lines are placed in the web, and the web is sheared into sheets. At the facility where the container is to be used, the sheet is folded along the fold lines to form the container.
There are many different types of containers, some having separate ends, bottoms, and tops formed of other sheets and glued together. Some containers are folded in different configurations than others. While these containers are satisfactory, in many cases the walls do not need as much strength as is provided by conventional single ply corrugated paper, which has three layers. For example, in the case of metal cans, the cans themselves will support the weight of a stack of such boxes. Making the box entirely of three layer corrugated material results in a waste of paper.
One type of container used for cans consists of a corrugated paper bottom with short corrugated paper walls that extend less than the full length of the cans. Plastic wrap is secured over the cans and to the container bottom to prevent the cans from falling from the container. A disadvantage of this system is the great expense required for wrapping machinery to wrap the plastic.